(function() {

    const _object_pattern = /^[og]\s*(.+)?/; // mtllib file_reference

    const _material_library_pattern = /^mtllib /; // usemtl material_name

    const _material_use_pattern = /^usemtl /; // usemap map_name

    const _map_use_pattern = /^usemap /;

    const _vA = new THREE.Vector3();

    const _vB = new THREE.Vector3();

    const _vC = new THREE.Vector3();

    const _ab = new THREE.Vector3();

    const _cb = new THREE.Vector3();

    function ParserState() {

        const state = {
            objects: [],
            object: {},
            vertices: [],
            normals: [],
            colors: [],
            uvs: [],
            materials: {},
            materialLibraries: [],
            startObject: function(name, fromDeclaration) {

                // If the current object (initial from reset) is not from a g/o declaration in the parsed
                // file. We need to use it for the first parsed g/o to keep things in sync.
                if (this.object && this.object.fromDeclaration === false) {

                    this.object.name = name;
                    this.object.fromDeclaration = fromDeclaration !== false;
                    return;

                }

                const previousMaterial = this.object && typeof this.object.currentMaterial === 'function' ? this.object.currentMaterial() : undefined;

                if (this.object && typeof this.object._finalize === 'function') {

                    this.object._finalize(true);

                }

                this.object = {
                    name: name || '',
                    fromDeclaration: fromDeclaration !== false,
                    geometry: {
                        vertices: [],
                        normals: [],
                        colors: [],
                        uvs: [],
                        hasUVIndices: false
                    },
                    materials: [],
                    smooth: true,
                    startMaterial: function(name, libraries) {

                        const previous = this._finalize(false); // New usemtl declaration overwrites an inherited material, except if faces were declared
                        // after the material, then it must be preserved for proper MultiMaterial continuation.


                        if (previous && (previous.inherited || previous.groupCount <= 0)) {

                            this.materials.splice(previous.index, 1);

                        }

                        const material = {
                            index: this.materials.length,
                            name: name || '',
                            mtllib: Array.isArray(libraries) && libraries.length > 0 ? libraries[libraries.length - 1] : '',
                            smooth: previous !== undefined ? previous.smooth : this.smooth,
                            groupStart: previous !== undefined ? previous.groupEnd : 0,
                            groupEnd: -1,
                            groupCount: -1,
                            inherited: false,
                            clone: function(index) {

                                const cloned = {
                                    index: typeof index === 'number' ? index : this.index,
                                    name: this.name,
                                    mtllib: this.mtllib,
                                    smooth: this.smooth,
                                    groupStart: 0,
                                    groupEnd: -1,
                                    groupCount: -1,
                                    inherited: false
                                };
                                cloned.clone = this.clone.bind(cloned);
                                return cloned;

                            }
                        };
                        this.materials.push(material);
                        return material;

                    },
                    currentMaterial: function() {

                        if (this.materials.length > 0) {

                            return this.materials[this.materials.length - 1];

                        }

                        return undefined;

                    },
                    _finalize: function(end) {

                        const lastMultiMaterial = this.currentMaterial();

                        if (lastMultiMaterial && lastMultiMaterial.groupEnd === -1) {

                            lastMultiMaterial.groupEnd = this.geometry.vertices.length / 3;
                            lastMultiMaterial.groupCount = lastMultiMaterial.groupEnd - lastMultiMaterial.groupStart;
                            lastMultiMaterial.inherited = false;

                        } // Ignore objects tail materials if no face declarations followed them before a new o/g started.


                        if (end && this.materials.length > 1) {

                            for (let mi = this.materials.length - 1; mi >= 0; mi--) {

                                if (this.materials[mi].groupCount <= 0) {

                                    this.materials.splice(mi, 1);

                                }

                            }

                        } // Guarantee at least one empty material, this makes the creation later more straight forward.


                        if (end && this.materials.length === 0) {

                            this.materials.push({
                                name: '',
                                smooth: this.smooth
                            });

                        }

                        return lastMultiMaterial;

                    }
                }; // Inherit previous objects material.
                // Spec tells us that a declared material must be set to all objects until a new material is declared.
                // If a usemtl declaration is encountered while this new object is being parsed, it will
                // overwrite the inherited material. Exception being that there was already face declarations
                // to the inherited material, then it will be preserved for proper MultiMaterial continuation.

                if (previousMaterial && previousMaterial.name && typeof previousMaterial.clone === 'function') {

                    const declared = previousMaterial.clone(0);
                    declared.inherited = true;
                    this.object.materials.push(declared);

                }

                this.objects.push(this.object);

            },
            finalize: function() {

                if (this.object && typeof this.object._finalize === 'function') {

                    this.object._finalize(true);

                }

            },
            parseVertexIndex: function(value, len) {

                const index = parseInt(value, 10);
                return (index >= 0 ? index - 1 : index + len / 3) * 3;

            },
            parseNormalIndex: function(value, len) {

                const index = parseInt(value, 10);
                return (index >= 0 ? index - 1 : index + len / 3) * 3;

            },
            parseUVIndex: function(value, len) {

                const index = parseInt(value, 10);
                return (index >= 0 ? index - 1 : index + len / 2) * 2;

            },
            addVertex: function(a, b, c) {

                const src = this.vertices;
                const dst = this.object.geometry.vertices;
                dst.push(src[a + 0], src[a + 1], src[a + 2]);
                dst.push(src[b + 0], src[b + 1], src[b + 2]);
                dst.push(src[c + 0], src[c + 1], src[c + 2]);

            },
            addVertexPoint: function(a) {

                const src = this.vertices;
                const dst = this.object.geometry.vertices;
                dst.push(src[a + 0], src[a + 1], src[a + 2]);

            },
            addVertexLine: function(a) {

                const src = this.vertices;
                const dst = this.object.geometry.vertices;
                dst.push(src[a + 0], src[a + 1], src[a + 2]);

            },
            addNormal: function(a, b, c) {

                const src = this.normals;
                const dst = this.object.geometry.normals;
                dst.push(src[a + 0], src[a + 1], src[a + 2]);
                dst.push(src[b + 0], src[b + 1], src[b + 2]);
                dst.push(src[c + 0], src[c + 1], src[c + 2]);

            },
            addFaceNormal: function(a, b, c) {

                const src = this.vertices;
                const dst = this.object.geometry.normals;

                _vA.fromArray(src, a);

                _vB.fromArray(src, b);

                _vC.fromArray(src, c);

                _cb.subVectors(_vC, _vB);

                _ab.subVectors(_vA, _vB);

                _cb.cross(_ab);

                _cb.normalize();

                dst.push(_cb.x, _cb.y, _cb.z);
                dst.push(_cb.x, _cb.y, _cb.z);
                dst.push(_cb.x, _cb.y, _cb.z);

            },
            addColor: function(a, b, c) {

                const src = this.colors;
                const dst = this.object.geometry.colors;
                if (src[a] !== undefined) dst.push(src[a + 0], src[a + 1], src[a + 2]);
                if (src[b] !== undefined) dst.push(src[b + 0], src[b + 1], src[b + 2]);
                if (src[c] !== undefined) dst.push(src[c + 0], src[c + 1], src[c + 2]);

            },
            addUV: function(a, b, c) {

                const src = this.uvs;
                const dst = this.object.geometry.uvs;
                dst.push(src[a + 0], src[a + 1]);
                dst.push(src[b + 0], src[b + 1]);
                dst.push(src[c + 0], src[c + 1]);

            },
            addDefaultUV: function() {

                const dst = this.object.geometry.uvs;
                dst.push(0, 0);
                dst.push(0, 0);
                dst.push(0, 0);

            },
            addUVLine: function(a) {

                const src = this.uvs;
                const dst = this.object.geometry.uvs;
                dst.push(src[a + 0], src[a + 1]);

            },
            addFace: function(a, b, c, ua, ub, uc, na, nb, nc) {

                const vLen = this.vertices.length;
                let ia = this.parseVertexIndex(a, vLen);
                let ib = this.parseVertexIndex(b, vLen);
                let ic = this.parseVertexIndex(c, vLen);
                this.addVertex(ia, ib, ic);
                this.addColor(ia, ib, ic); // normals

                if (na !== undefined && na !== '') {

                    const nLen = this.normals.length;
                    ia = this.parseNormalIndex(na, nLen);
                    ib = this.parseNormalIndex(nb, nLen);
                    ic = this.parseNormalIndex(nc, nLen);
                    this.addNormal(ia, ib, ic);

                } else {

                    this.addFaceNormal(ia, ib, ic);

                } // uvs


                if (ua !== undefined && ua !== '') {

                    const uvLen = this.uvs.length;
                    ia = this.parseUVIndex(ua, uvLen);
                    ib = this.parseUVIndex(ub, uvLen);
                    ic = this.parseUVIndex(uc, uvLen);
                    this.addUV(ia, ib, ic);
                    this.object.geometry.hasUVIndices = true;

                } else {

                    // add placeholder values (for inconsistent face definitions)
                    this.addDefaultUV();

                }

            },
            addPointGeometry: function(vertices) {

                this.object.geometry.type = 'Points';
                const vLen = this.vertices.length;

                for (let vi = 0, l = vertices.length; vi < l; vi++) {

                    const index = this.parseVertexIndex(vertices[vi], vLen);
                    this.addVertexPoint(index);
                    this.addColor(index);

                }

            },
            addLineGeometry: function(vertices, uvs) {

                this.object.geometry.type = 'Line';
                const vLen = this.vertices.length;
                const uvLen = this.uvs.length;

                for (let vi = 0, l = vertices.length; vi < l; vi++) {

                    this.addVertexLine(this.parseVertexIndex(vertices[vi], vLen));

                }

                for (let uvi = 0, l = uvs.length; uvi < l; uvi++) {

                    this.addUVLine(this.parseUVIndex(uvs[uvi], uvLen));

                }

            }
        };
        state.startObject('', false);
        return state;

    } //


    class OBJLoader extends THREE.Loader {

        constructor(manager) {

            super(manager);
            this.materials = null;

        }

        load(url, onLoad, onProgress, onError) {

            const scope = this;
            const loader = new THREE.FileLoader(this.manager);
            loader.setPath(this.path);
            loader.setRequestHeader(this.requestHeader);
            loader.setWithCredentials(this.withCredentials);
            loader.load(url, function(text) {

                try {

                    onLoad(scope.parse(text));

                } catch (e) {

                    if (onError) {

                        onError(e);

                    } else {

                        console.error(e);

                    }

                    scope.manager.itemError(url);

                }

            }, onProgress, onError);

        }

        setMaterials(materials) {

            this.materials = materials;
            return this;

        }

        parse(text) {

            const state = new ParserState();

            if (text.indexOf('\r\n') !== -1) {

                // This is faster than String.split with regex that splits on both
                text = text.replace(/\r\n/g, '\n');

            }

            if (text.indexOf('\\\n') !== -1) {

                // join lines separated by a line continuation character (\)
                text = text.replace(/\\\n/g, '');

            }

            const lines = text.split('\n');
            let line = '',
                lineFirstChar = '';
            let lineLength = 0;
            let result = []; // Faster to just trim left side of the line. Use if available.

            const trimLeft = typeof ''.trimLeft === 'function';

            for (let i = 0, l = lines.length; i < l; i++) {

                line = lines[i];
                line = trimLeft ? line.trimLeft() : line.trim();
                lineLength = line.length;
                if (lineLength === 0) continue;
                lineFirstChar = line.charAt(0); // @todo invoke passed in handler if any

                if (lineFirstChar === '#') continue;

                if (lineFirstChar === 'v') {

                    const data = line.split(/\s+/);

                    switch (data[0]) {

                        case 'v':
                            state.vertices.push(parseFloat(data[1]), parseFloat(data[2]), parseFloat(data[3]));

                            if (data.length >= 7) {

                                state.colors.push(parseFloat(data[4]), parseFloat(data[5]), parseFloat(data[6]));

                            } else {

                                // if no colors are defined, add placeholders so color and vertex indices match
                                state.colors.push(undefined, undefined, undefined);

                            }

                            break;

                        case 'vn':
                            state.normals.push(parseFloat(data[1]), parseFloat(data[2]), parseFloat(data[3]));
                            break;

                        case 'vt':
                            state.uvs.push(parseFloat(data[1]), parseFloat(data[2]));
                            break;

                    }

                } else if (lineFirstChar === 'f') {

                    const lineData = line.substr(1).trim();
                    const vertexData = lineData.split(/\s+/);
                    const faceVertices = []; // Parse the face vertex data into an easy to work with format

                    for (let j = 0, jl = vertexData.length; j < jl; j++) {

                        const vertex = vertexData[j];

                        if (vertex.length > 0) {

                            const vertexParts = vertex.split('/');
                            faceVertices.push(vertexParts);

                        }

                    } // Draw an edge between the first vertex and all subsequent vertices to form an n-gon


                    const v1 = faceVertices[0];

                    for (let j = 1, jl = faceVertices.length - 1; j < jl; j++) {

                        const v2 = faceVertices[j];
                        const v3 = faceVertices[j + 1];
                        state.addFace(v1[0], v2[0], v3[0], v1[1], v2[1], v3[1], v1[2], v2[2], v3[2]);

                    }

                } else if (lineFirstChar === 'l') {

                    const lineParts = line.substring(1).trim().split(' ');
                    let lineVertices = [];
                    const lineUVs = [];

                    if (line.indexOf('/') === -1) {

                        lineVertices = lineParts;

                    } else {

                        for (let li = 0, llen = lineParts.length; li < llen; li++) {

                            const parts = lineParts[li].split('/');
                            if (parts[0] !== '') lineVertices.push(parts[0]);
                            if (parts[1] !== '') lineUVs.push(parts[1]);

                        }

                    }

                    state.addLineGeometry(lineVertices, lineUVs);

                } else if (lineFirstChar === 'p') {

                    const lineData = line.substr(1).trim();
                    const pointData = lineData.split(' ');
                    state.addPointGeometry(pointData);

                } else if ((result = _object_pattern.exec(line)) !== null) {

                    // o object_name
                    // or
                    // g group_name
                    // WORKAROUND: https://bugs.chromium.org/p/v8/issues/detail?id=2869
                    // let name = result[ 0 ].substr( 1 ).trim();
                    const name = (' ' + result[0].substr(1).trim()).substr(1);
                    state.startObject(name);

                } else if (_material_use_pattern.test(line)) {

                    // material
                    state.object.startMaterial(line.substring(7).trim(), state.materialLibraries);

                } else if (_material_library_pattern.test(line)) {

                    // mtl file
                    state.materialLibraries.push(line.substring(7).trim());

                } else if (_map_use_pattern.test(line)) {

                    // the line is parsed but ignored since the loader assumes textures are defined MTL files
                    // (according to https://www.okino.com/conv/imp_wave.htm, 'usemap' is the old-style Wavefront texture reference method)
                    console.warn('THREE.OBJLoader: Rendering identifier "usemap" not supported. Textures must be defined in MTL files.');

                } else if (lineFirstChar === 's') {

                    result = line.split(' '); // smooth shading
                    // @todo Handle files that have varying smooth values for a set of faces inside one geometry,
                    // but does not define a usemtl for each face set.
                    // This should be detected and a dummy material created (later MultiMaterial and geometry groups).
                    // This requires some care to not create extra material on each smooth value for "normal" obj files.
                    // where explicit usemtl defines geometry groups.
                    // Example asset: examples/models/obj/cerberus/Cerberus.obj

                    /*
                     * http://paulbourke.net/dataformats/obj/
                     * or
                     * http://www.cs.utah.edu/~boulos/cs3505/obj_spec.pdf
                     *
                     * From chapter "Grouping" Syntax explanation "s group_number":
                     * "group_number is the smoothing group number. To turn off smoothing groups, use a value of 0 or off.
                     * Polygonal elements use group numbers to put elements in different smoothing groups. For free-form
                     * surfaces, smoothing groups are either turned on or off; there is no difference between values greater
                     * than 0."
                     */

                    if (result.length > 1) {

                        const value = result[1].trim().toLowerCase();
                        state.object.smooth = value !== '0' && value !== 'off';

                    } else {

                        // ZBrush can produce "s" lines #11707
                        state.object.smooth = true;

                    }

                    const material = state.object.currentMaterial();
                    if (material) material.smooth = state.object.smooth;

                } else {

                    // Handle null terminated files without exception
                    if (line === '\0') continue;
                    console.warn('THREE.OBJLoader: Unexpected line: "' + line + '"');

                }

            }

            state.finalize();
            const container = new THREE.Group();
            container.materialLibraries = [].concat(state.materialLibraries);
            const hasPrimitives = !(state.objects.length === 1 && state.objects[0].geometry.vertices.length === 0);

            if (hasPrimitives === true) {

                for (let i = 0, l = state.objects.length; i < l; i++) {

                    const object = state.objects[i];
                    const geometry = object.geometry;
                    const materials = object.materials;
                    const isLine = geometry.type === 'Line';
                    const isPoints = geometry.type === 'Points';
                    let hasVertexColors = false; // Skip o/g line declarations that did not follow with any faces

                    if (geometry.vertices.length === 0) continue;
                    const buffergeometry = new THREE.BufferGeometry();
                    buffergeometry.setAttribute('position', new THREE.Float32BufferAttribute(geometry.vertices, 3));

                    if (geometry.normals.length > 0) {

                        buffergeometry.setAttribute('normal', new THREE.Float32BufferAttribute(geometry.normals, 3));

                    }

                    if (geometry.colors.length > 0) {

                        hasVertexColors = true;
                        buffergeometry.setAttribute('color', new THREE.Float32BufferAttribute(geometry.colors, 3));

                    }

                    if (geometry.hasUVIndices === true) {

                        buffergeometry.setAttribute('uv', new THREE.Float32BufferAttribute(geometry.uvs, 2));

                    } // Create materials


                    const createdMaterials = [];

                    for (let mi = 0, miLen = materials.length; mi < miLen; mi++) {

                        const sourceMaterial = materials[mi];
                        const materialHash = sourceMaterial.name + '_' + sourceMaterial.smooth + '_' + hasVertexColors;
                        let material = state.materials[materialHash];

                        if (this.materials !== null) {

                            material = this.materials.create(sourceMaterial.name); // mtl etc. loaders probably can't create line materials correctly, copy properties to a line material.

                            if (isLine && material && !(material instanceof THREE.LineBasicMaterial)) {

                                const materialLine = new THREE.LineBasicMaterial();
                                THREE.Material.prototype.copy.call(materialLine, material);
                                materialLine.color.copy(material.color);
                                material = materialLine;

                            } else if (isPoints && material && !(material instanceof THREE.PointsMaterial)) {

                                const materialPoints = new THREE.PointsMaterial({
                                    size: 10,
                                    sizeAttenuation: false
                                });
                                THREE.Material.prototype.copy.call(materialPoints, material);
                                materialPoints.color.copy(material.color);
                                materialPoints.map = material.map;
                                material = materialPoints;

                            }

                        }

                        if (material === undefined) {

                            if (isLine) {

                                material = new THREE.LineBasicMaterial();

                            } else if (isPoints) {

                                material = new THREE.PointsMaterial({
                                    size: 1,
                                    sizeAttenuation: false
                                });

                            } else {

                                material = new THREE.MeshPhongMaterial();

                            }

                            material.name = sourceMaterial.name;
                            material.flatShading = sourceMaterial.smooth ? false : true;
                            material.vertexColors = hasVertexColors;
                            state.materials[materialHash] = material;

                        }

                        createdMaterials.push(material);

                    } // Create mesh


                    let mesh;

                    if (createdMaterials.length > 1) {

                        for (let mi = 0, miLen = materials.length; mi < miLen; mi++) {

                            const sourceMaterial = materials[mi];
                            buffergeometry.addGroup(sourceMaterial.groupStart, sourceMaterial.groupCount, mi);

                        }

                        if (isLine) {

                            mesh = new THREE.LineSegments(buffergeometry, createdMaterials);

                        } else if (isPoints) {

                            mesh = new THREE.Points(buffergeometry, createdMaterials);

                        } else {

                            mesh = new THREE.Mesh(buffergeometry, createdMaterials);

                        }

                    } else {

                        if (isLine) {

                            mesh = new THREE.LineSegments(buffergeometry, createdMaterials[0]);

                        } else if (isPoints) {

                            mesh = new THREE.Points(buffergeometry, createdMaterials[0]);

                        } else {

                            mesh = new THREE.Mesh(buffergeometry, createdMaterials[0]);

                        }

                    }

                    mesh.name = object.name;
                    container.add(mesh);

                }

            } else {

                // if there is only the default parser state object with no geometry data, interpret data as point cloud
                if (state.vertices.length > 0) {

                    const material = new THREE.PointsMaterial({
                        size: 1,
                        sizeAttenuation: false
                    });
                    const buffergeometry = new THREE.BufferGeometry();
                    buffergeometry.setAttribute('position', new THREE.Float32BufferAttribute(state.vertices, 3));

                    if (state.colors.length > 0 && state.colors[0] !== undefined) {

                        buffergeometry.setAttribute('color', new THREE.Float32BufferAttribute(state.colors, 3));
                        material.vertexColors = true;

                    }

                    const points = new THREE.Points(buffergeometry, material);
                    container.add(points);

                }

            }

            return container;

        }

    }

    THREE.OBJLoader = OBJLoader;

})();